Scale
drawn : real
model : projection
T/F: An oblique projection is a kind of perspective projection
False: Oblique = parallel projection
T/F: An isometric projection is a kind of parallel projection
True
T/F: When lettering space the letters so that the space BETWEEN each letters is always equal
False: The letters should be spaced so background areas appear equal
What projection view is this?
THIRD angle projection
Views produced if the observer is outside looking in
What projection view is this?
FIRST angle projection
object is in front of the vertical plane
Is this drawing 1st or 3rd angle projection?
Top looking down = THIRD angle projection
Is this drawing 1st or 3rd angle projection?
FIRST angle proj
Rules for hidden lines:
should touch edge of solid line border
Only exception is curved tangent lines. Should NOT touch surface
hidden lines should connect with each other at corners
What are centrelines used for?
show the axis of symmetry
Shown location of holes and circular patters
Precedence of Lines
Visible > Hidden > Centreline
T/F: Show adjacent tangent lines?
False:
Intersections and Tangencies with curved surfaces:
When is a line shown vs no line?
Intersections of Cylinders:
What will the drawing look like?
Intersections of Cylinders:
What will the drawing look like?
Intersections of Cylinders:
What will the drawing look like?
Conventional edges:
How do you add lines to depict rounded and filleted edges?
small “y” shapes
round corners
Conventional Breaks:
Round Solid
Conventional Breaks:
Round Tubular
Conventional Breaks:
Rectangular
Conventional Breaks:
Wood
Revolution Conventions
draw mirrored instead of keeping realistic angles
Rules for Lines in Section Views
show edges that are now visible, colour with hatched lines
No hidden lines
Can’t cross sectioned area
Cutting arrows point away
Rules for drawing section cuts
show edges that are now visible, colour with hatched lines
No hidden lines
Can’t cross sectioned area
Cutting arrows point away
T/F: In section views, hatch crosses visible line
False!
drawing for cutting plane direction:
Visualizing cutting plane direction:
What does a half section look like?
What does a broken out section look like?
Show revolved section view for this part:
What is an offset section?
showing features not in a straight line
T/F: Ribs in Section cuts are hatched
False! Not hatched even though cutting plane slices them
Create an aligned section with this part:
Show the hatching for this Assembly
How to find true length of a line using auxiliary views?
make fold line parallel to line you want to show true length to
How to show the true size of an oblique surface?
What is a Dihedral angle?
the angle between two planes
Proper dimension and Extension lines rules
do not cross dimension lines
Do not go inside shape
What is a Leader?
thin solid line pointing to a note or dimension
Starts a with arrowhead or dot
Should be parallel, but not horizontal or vertical
Dual dimensioning. How to tell difference between mm and inch?
MM / Inch
Inches are in brackets mm/(inch)
Unnecessary (Superfluous) Dimension rules
no repeated dimensions, use “X” times notation.
No diagonal diameter
What are Finish Marks?
indicate surface is not smooth
Marked with a little V opposite the line
What is tolerance?
The amount a specific dimension can vary
What is a CLEARANCE fit?
When parts fit together with some space between them
What is an INTERFERENCE fit?
one part is larger than the other, have to force them together
General tolerance notes rules
in lower right corner of sheet near title block
In form of: “All Tolerances +- Xmm unless otherwise noted”
What are limit tolerances?
State the upper and lower limits for the dimension range in place of the dimension values
Upper limit above lower one
What are Unilateral tolerances?
When the tolerance applies in only one direction (other value is 0)
What are Bilateral tolerances?
when non zero values are added or subtracted
What do Angular Tolerances look like?
bilateral
in degrees
Chained Dimensioning: What are the tolerances of 1 and 2?
Dimensioning Limits 1: [1.990, 2.000]
Dimensioning Limits 2: [2.985, 3.000]
Baseline dimensioning:
What are the tolerances of 1 and 2 (use X, Y, Z)
Line 1: [0.995, 1.005] (Max at MaxZ-MinY, Min at MinZ-MaxY)
Line 2: [0.995, 1.005] = [ZMin-Ymax, ZMax-Ymin]
ANSI B4.1:
What is RC the symbol for?
Clearance fits (running/sliding fits)
ANSI B4.1:
Symbol: LC
LC = Locational (clearance fits)
ANSI B4.1:
Symbol: LT
LT = Locational (Tension clearance / interference fits)
ANSI B4.1:
Symbol: LN
LN = Locational (Locational interference fits)
ANSI B4.1:
Symbol: FN
FN = Interference (Force/shrink fits)
Metric System for Mating Parts:
Method of writing a HOLE:
Size Deviation ITGrade
50H8
H8 = tolerance grade
Metric System for Mating Parts:
Method of writing a SHAFT:
Size deviation ITGrade
50f7
f7=tolerance grade
Metric System for Mating Parts:
Method of writing a FIT:
Size HoleTolerance / ShaftTolerance
50H8/f7
H8/f7 = Fit
What does a datum featuring a surface /extension line look like?
What does a datum featuring size look like for flat surfaces?
What does a datum featuring size look like for cylindrical surfaces?
What does a datum features control frame look like?
What does Maximum Material Condition (MMC) look like?
Symbol: Flatness Tolerance?
Tolerance zone defined by two parallel planes within which the surface must lie
Symbol: Circularity / Roundness
tolerance zone where circular element lies within 2 concentric circles
Symbol: Cylindricity tolerance
specifies tolerance zone bounded by 2 concentric cylinders where the surface must lie
What is the difference between circularity and cylindricity?
circularity focused with measurements around the surface in one circle
Cylindricity takes into account how straight the axial portion of the cylinder is
If a shaft satisfies circularity, will it satisfy cylindricity?
Not necessarily. Circularity = circle, cylindricity = circle + straight. - Cones can pass circularity, but a cone is not a cylinder
What is the coin example for cylindricity and circularity?
Imagine a stack of coins.
Cylindricity measures if entire stack is straight up and every coin is round
Circularity only be measurements of roundness for coins
If a shaft satisfy cylindricity, will it satisfy circularity?
Yes because cylindricity has circularity inside of it. (Circle portion)
What is the profile tolerance?
Specifies a uniform/nonuniform boundary along true proful
What is the angularity tolerance?
specifies tolerance zone between 2 parallel planes with reference to angle from datum plane
What is Parallelism tolerance?
Specifies tolerance zone between 2 parallel planes or lines parallel to datum plan/axis
What is Perpendicularity tolerance?
Specifies tolerance zone between 2 parallel planes perpendicular to datum plan/axis
What is Concentricity tolerance?
defines spherical/cylindrical tolerance zone where median points lie within tolerance zone
What is Circular Runout?
Controls the variation of a circular cross section
Symbol is single arrow
What is total runout
Controls variation of entire surface
double parallel arrow
What are the 3 basic applications of threads?
hold parts together
Adjustment between parts
Transmit power
Screw thread terms: Difference between minor, major, and pitch diameters?
Major: edge to creast
Minor: root to root (inner swirls)
Pitch: average b/w major and minor??
What is a right hand thread?
turns CLOCKWISE
Threads slanted towards advancement direction
What is a left hand thread?
turns COUNTERCLOCKWISE
Threads slanted away from advance direction
What is the relationship between Lead and Starts with threading?
Starts = how many different starts that are visible at end view of bolt
Lead = # of Starts
Threading: Difference between pitch and lead?
Pitch = distance between adjacent threads
Lead = #of pitches from the mirrored thread slope line to the end of the bolt
Show drawing of schematic threading
show jig jags of threading in section view
In full view, long lines to represent threads
Show simplified threading drawing
uses DASHED (hidden) lines for section and full view
What is the way to write metric thread notes?
M ThreadForm PitchDiameter x Pitch
MJ10 × 1.5
What is the way to write imperial thread notes?
#pitch / inch
Inch = dashed line (-)
1.125-5 ACME
What are Spur gears?
Have teeth on cylindrical surfaces that transmit power without slipping
If the rotational speed w2/w1 = 2:1, and gear 1 has 30 teeth, find number of teeth for gear 2
Gear 2 teeth = 60
If the rotational speed w2/w1 = 2:1, and gear 1 has diameter = 60 what is diameter for gear 2?
Diameter 2 = 120mm
Working drawings of spur gears (3 circles)
What is the difference between Addendum, pitch, and root circles?
Addendum: arc on top of gear teeth
pitch: halfway through gear teeth, DASHED LINE
Root: arc on bottom of gear teeth/bottom land
New CDP requirements
any activity that enhances technical, ethical, management, leadership, communication skills And knowledge
5 online learning modules each year
Personal annual competency evaluation (PACE) plan
Technical activities
One non technical activity (leadership, comms, ethics)
What are the requirements for Continuning Professional Development? (CPD) by APEGA (3)
240 CDP hours over 3 years
Activities in 3/6 categories
Cannot claim more than maximum in each category
6 categories for CPD
professional (job)
Formal Activity (courses)
Informal activity (conferences)
Participation (services)
Presentations (seminar)
Contributions to knowledge (paper)
Why is lifelong learning important?
more likely to be satisfied with jobs
Improved problem solving skills
Develop critical thinking
Remain relevant and competitive in job field